Means for compensating the forces in voltage regulators



Jan. 22, 1929. 1,700,042

H. GROB MEANS FOR COIPENSATING THE FORCES IN VOLTAGE REGULATORS FiledDec. 16, 1927 en far:

k 4 fine. s hb mg Patented Jan. 22, 1929.

UNITED STATES PATENT OFFICE.

nueo once, or BERLIN, GERMANY.

, Application filed December 16, 1927, Serial No. 240,595, and inGermany December 16, 192 6.'

This invention relates to electrical regulating apparatus and moreparticularly to such ture or production. Another object is to provide aregulating apparatus in which a pressure responsive variable resistanceis employed adapted to permit a convenient, rapid and thoroughlydependable predetermination of .the range and character of operation, aswell as of compensation or balancing of the acting forces to beachieved. A.nother object is to provide a regulating apparatus of theabove-mentioned character that will be of inexpensive construction, ofthoroughly dependable and controllable action, and well adapted to meetthe varying conditions met with in the course of manufacture or in thecourse of actual practical use. Other objects will be in part obvious orin part pointed out hereinafter.

The invention accordingly consists in the features of construction,combinations of elements, and arrangements of parts as will beexemplified in the structure to be hereinafter described and the scopeof the application of which will be indicated in the following claims Inthe accompanying drawing in which is shown one of-various possibleembodiments of my invention, the single figure shows in front elevation,partly in section and partly diagrammatically, an assembled regulatingapparatus.

As conducive to a clearer understanding of certain features of thisinvent-ion, it might be noted at this point that an electric regulatingapparatus embodying a pressure responsive resistance device such as acarbon pile, has many desirable advantages, but that certaindifficulties are attendant upon the construction and operation of suchan apparatus due,

' for example, to the fact that the resistance to compression or thereactive force of the carbon pile increases as the compression of thecarbon pile increases in a manner that is not shown at A anelectromagnet which may be uniform but varying. In fact, the reactiveforce first increases gradually as the compression proceeds andthereafter increases more rapidly as the compression advances andapproaches a maximum, Ordinarily an elec troniagnet or the like isemployed to relieve the pressure on the carbon pile while a spring isemployed to compress the carbon pile. The forces of the electromagnetand of the spring, and the reactive force of the carbon pile should bebrought into mechanical equilibrium over the entire desired range ofcompression of the carbon pile.

According to a preferred form of mechanism for achieving quickly suchmechanical equilibrium, the spring is arranged to act upon thecarbon-pile through a cord, cable or the like, resting against asuitably curved memher, the arrangement being such that by reason of thecurved member the distance of the cord from the fulcrum about which thecurved element pivots, and hence the lever arm through which the springand cord act upon the carbon pile, are so changed that for each positionof the mechanism the desired equilibrium of the mechanical forces actingis brought about.

This curved element is of peculiar shape due in part to the peculiarvariation in the reactive force of the carbon pile; and due to variousfactors that either cannot be elimi-' natedor cannot be fully controlledsuch as, for example, variations in thematerials employed, the range oftolerances necessary in manufacture, and the like, it is exceedinglydifficult, if not impossible, to employan identically curved element forall of the various regulating devices undergoing manufacture, if thesedevices are to have uniformly the intended or desired characteristics.Either all of the devices thus manufactured do not have the samecharacteristics of control or operation in the regulating action or elsethe individual devices and particularly the curved.

members have to be separately worked up or re-shaped or modified,mainlyby laborious hand methods, in the endeavor to achieve'the intendedoperating characteristics. One of the dominant aims of thisinvention isto provide a regulating apparatus in which such disadvantages as thoseimmediately above noted are effectively overcome and in a mannerthoroughly practical and simple and well adapted to meet therequirements of inexpensive and rapid quantity manufacture.

Referring now to the drawing, there is excited in any suitable manner,as for example by a function of the electrical circuit or conditions tobe regulated; b Way of further example the magnet A may e excited by thevoltage of, for example, a dynamo so that the regulating apparatus isvoltage responsive where the v tage of the dynamo. is intended to bemaintained at a constant value. A column or pile composed of carbondisks, shown at E, may be connected in the exciter circuit of thedynamo, in the above-assumed illustration, so that the excitation of thedynamo may be varied in order to control the voltage of the dynamo.

An armature Bis pivoted at K and is thus mounted to be acted upon by theelectromagnet AJ A knife edge F is mounted on the armature B and actsupon the free end of the carbon pile E, the other end of which is fixedor anchored in an. suitable manner, as is diaj grammatically s own inthe drawing. A spring 0 acts upon the armature B in adirection to opposethe pull on the latter by the magnet A and hence in a direction to applypressure to the carbon ile E.

As soon as the energization of the magnet A exceeds a predeterminedvalue, for example, exceeds a value corresponding to that of the voltageintended to be maintained constant, the magnet draws the armatureB incounter 'clockwise direction about the pivot K and against the action ofthe spring C, thus decreasing the pressure on the carbon column or pileE, theresistance of the latter bein accordingly varied. 7

e above action ceases as soon as the voltage value desired to bemaintained constant 'isrestored and mechanical equilibriumpf suchforces-as the three -hereinabove mentioned is then achieved. Moreover,such equilibrium'shouldbe achieved throughout the intended range ofaction of'the regulator and hence these forces should be compensated forand balanced throughout the entire operative range of movement of idlearmature B.

The armature B will be seen from the drawing 'to'be substantiallyL-shaped, havingasubstantially upstanding arm or bracket M adjacentthefulcrum point K. Mounted uponthe bracket M isa curved element G,

- more clearly described hereinafter; the element G is provided with twothreaded pins L fixed thereto, each passing through an opening in thebracket M and each being provided with nuts 0. Inter osed between thecurved element G and the racket M and about the pins L are sprin N.

The element is sha d to provide an outer curved surface (in icated bythe righthand curved edge of the member G) against which rests the cordor cable D, the latter being secured at its upper end to the up er endof the curved mem er G'and secured at its lower end to the spring C.

The armature B and hence the curved member G carried by it arefulcrufned at K, the fulcrum point being preferably in the formsubstantially of a knife edge, as shown in the drawing. The curvedsurface pro vided by the member G is so shaped that as the latter swingsabout the pivot K the lever arm through which the spring G 'acts changescurvature of the member G is so chosen that throughout the range ofaction of the regulator the force exerted by the spring continuallycounterbalances the pull of the magnet plus the reactive force of thecarbon pile. Substantial equilibrium or balance of the parts prevails ineach position of the arma- .ture throughout its entire range ofmovement. The member G is given a curvature appropriate to achieve theaboize-described actions, it being understood that the member G may bemade in large quantities and of identical construction and shapethroughout,

However, becausev of various factors due, for example, to uncontrollablevariations in the material used, non-uniformity of action of the varioussprings, the magnetic qualities 0 the iron used in the ample suchvariables as occur within. the range of tolerances necessarily permittedin the construction and manufacture of the various-parts, it ispossible. that the member G ssible variation in' Jnagnetic circuit andby way of further exeven though initially carefully predetermined as tocurvature, has its action modified by such factors as'above noted by wayof-example. Accordingl when the regulating apparatus is assemb edand-tested or in-.

stalled to give it its intended operating characteristics, these factorsare dependably overthe bracket M, the relation of the predeterminedcurved membervG to the parts with which it coacts. The pins L will beseen to be spaced substantially and by means of the nuts 0 and thecoaction therewith of the springs N, an upper point and substantially alower point of the curved member G (corresponding respectively to thepoints of attachment of the'pins L come by predetermining', by means ofthe "manner in which the member G ismounted on and correspondingsubstantially to the two extremes of the range of operation of theregulator), may be empirically predetermined to achieve file intendedforce-compensating or equilibrium -establishing action above-described,and if thus two materially spaced points of the curved member Gcorresponding to two difierent points in the range of action of theapparatus are thus predetermined, it is found that, due to thepredetermined curvature of the member G, the remaining points in therange of operation of the apparatus will substantially bring about theintende action of the apparatus. I

Thus, it will be seen that there has been provided in this invention athoroughly practical and reliable regulating apparatus well adapted tomeet the requirements of not only hard practical use but also ofinexpensive manufacture on a large scale and that the various variablefactors that have to be contended with in the manufacture of suchapparatus are reliably overcome in a thoroughly simple and inexpensiveand economic manner.

As many possible embodiments may be made of the above invention and asmany changes might be made in the embodiment above set forth, it is tobe understood that all matter hereinbefore set forth or show'n'in theaccompanying drawing is to be interpreted as illustrative and not in alimiting sense.

I claim:

1. In electrical regulating apparatus, in combination, a pressurecontrolled variable resistance element, a coil, a pivoted member actedupon by said coil and mechanically connected to vary the compression ofsaid resistance element, a spring, means connecting said spring to saidmember and including a flexible cable connecting said spring to saidmember and a curved element adapted to change the lever arm throughwhich said spring acts as said pivoted member moves about its pivot, andmeans mounting said curved element upon .said pivoted member andincluding a pair of devices spaced lengthwise of said curved element,and means for predetermining the displacement of said devices from the 4fulcrum of said pivoted member.

2. In electrical regulating apparatus, in combination, a pressurecontrolled variable resistance element, a coil, a pivoted member actedupon by said coil and mechanically connected to vary the compression ofsaidresistance element, a spring, means connecting said spring to saidmember and including a flexible cable connecting said spring to saidmember and a curved element adapted to change the leverarm through whichsaid spring acts as said pivoted member moves about its pivot, meansmounting said curved element upon said pivoted member and including anarm on said pivoted member, and means connecting said curved element tosaid arm at at least two spaced points of said curved element andadapted to permit predetermination of the displacement of one of saidpoints from said arm.

3, In electrical regulating apparatus, in combination, a pressurecont-rolled variable resistance element, a-coil, a pivoted member actedupon by said coil and mechanically connected to vary the compression ofsaid resistance element, a spring, means connecting said spring to saidmember and including a flexible cable connecting said spring to saidmember and a curved element adapted to combination, a pressurecontrolled variable resistance element, a coil, a pivoted member actedupon by said coil and mechanically connected to vary the compression ofsaid resistance element, a spring, means connecting said spring to saidmember and including a flexible cable connecting said spring to saidmember and a curved element adapted to change the lever arm throughwhich said spring acts as said pivoted member moves about its pivot,means mounting said curvedelement upon said pivoted member and includingan arm on said pivoted member, a plurality of pins on said curvedelement, and means securing said pins to said arm and adapted to permitadjustment of said pins and hence of said curved element in a directiontoward or away from said arm.

5. In electrical regulating apparatus, in cgmbination, a pressurecontrolled variable resistance element, a coil, a pivoted member actedupon by said coil and mechanically connected to vary the compression ofsaid resistance element, a spring, means connecting said spring to saidmember and including aflexible cable connecting said spring to saidmember and a curved element adapted to change the lever arm throughwhich said spring actsas said pivoted member moves about its pivot,means mounting said curved element upon said pivoted member andincluding an} arm on said pivoted member, a plurality of pins on saidcurved element, and means in uding spring means for securing sai-d'pins0 said arm and adapted to permit adjustment of saidlpins'and hence ofsaid curved element in a direction toward or away from said arm.

6. .,In electrical regulating apparatus, in combination, a pressure,controlled variable. resistance element, a coil, a pivoted member actedupon by said coil and mechanically connected to vary the compression ofsaid resistance'element, a spring, means connecting said spring to saidmember and including a flexible cable connecting said sprlng to saidmember and a curved element adapted to change the lever arm throughwhich said spring acts as said pivoted member moves about its pivot, andmeans mounting said curved element upon said pivoted member adapted topermit predetermination of the relation of said curved element to saidpivoted member.

7. In' electrical regulating apparatus, in combination, a compressiblecarbon pile; electromagnetic means for relieving the pressure thereon;spring n'icansacting to increase the pressure on said carbon pile; amember of predetermined curvature for compensating for the variation inthe reactive force of said carbon pile; and means mounting said curvedmember in operative relation to said spring, electromagnetic means, andcarbon pile adapted to permit predeterlnination of its relationthereto." p

8. In electrical regulating apparatus, in

combination, a compressible carbon pile, elec troma netic means forrelievin the ressure a thereon s rm" means actm to mcrease the i F-pressure on said carbon pile, means including a member of predeterminedcurvature for changing the lever arm throu h which said spring acts uponsaid ca rbon-p1le, and means] mounting said curved memberadapted to.per-

mit predetermination of its action in changing the lever arm of thesprin 1 9. In electrical regulating apparatus, in combination, acompressible carbon pile, an electromagnet having apivotedarmatureprovided with an arm extending substantially at ri ht angles thereto andadjacent j the pivot of said armature, means connecting said armature tosaid carbon pile to permit change in the pressure on the latter as saidY armature moves, a spring, means connecting said spring to said armcomprising a flexible cable and a member of predetermined sha e movablewith said arm and against which said flexible cable rests, said-memberbeing shaped to change the lever arm through which said spring acts, andmeans mounting said member of predetermined shape on said arm andadapted to permit at will a change in: the displacement of said memberrelative ber of predetermined sha e movable with said arm and againstwhic said flexible carblc rests, said member being" shaped to change thelever arm through which said spring acts,

and means at two spaced points for securing said member of predeterminedshape to said arm adapted to permit predetermination at "will oft-hedisplacement individually of said spaced points of said member from thepivot of said armature.

In testimony whereof I have aflixed my signature.

l-IUGO. GROB.

